Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cao phoi » cap phoi, cay phoi, cao phong
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
ve cac » va cac, vien cac
cua tu » cua tuc, cua su, cua cu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (hoc sach)) ky nang cao phoi. hieu ve cac nuoc va danh vi ((cua te) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (hoc sach)) ky nang cao phoi. hieu ve cac nuoc va danh vi ((cua te) OR (cua tu)).
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (hoc sach)) ky nang cao phoi. hieu ve cac nuoc va danh vi ((cua te) or (cua tu))*.